package com.itheima.servlet;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Enumeration;

public class ServletConfigDemo extends HttpServlet {

    private ServletConfig config;

    @Override
    public void init(ServletConfig config) throws ServletException {
        this.config= config;
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String encodingValue = config.getInitParameter("encoding");
        System.out.println(encodingValue);


        Enumeration <String> keys = config.getInitParameterNames();
        while (keys.hasMoreElements()){
            //获取每一个key
            String key = keys.nextElement();

            //根据key获取value
            String value = config.getInitParameter(key);

            System.out.println(key+","+value);
        }

        //获取Servlet的名称
        String servletName = config.getServletName();
        System.out.println(servletName);

        //获取ServletContext对象
        ServletContext servletContext = config.getServletContext();
        System.out.println(servletContext);

        //获取共享数据
        Object username = servletContext.getAttribute("username");
        System.out.println(username);


    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req,resp);
    }
}
